Piston ring



3 w.;. AMBERG 1,773,250

' PISTON RING Filed Feb. 4, 1929 2 V a I L 117% 24 tel Effl ibeg 34 2? J1 14: 2 7 j 6:

Patented Aug. 19, 1930 UNITED STATES PATENT OFFICE WALTER AMBEBG, 0F GLEN ELLYN, ILLINOIS, ASSIGNOB,

TO SMLLLEY ACCESSORIES GORYOBATION, OF C HICAGO,

or rumors BY MESNE Assmnmim'rs, armors, A coaroiwrxon PISTON BING- Application filed February 4, 1829. Serial 110. 387,202.

This invention, which is concerned gen orally with a piston ring, is directed more points throughout an increased period of service. A spring-havin the features of advantage above noted is i lustrated by way of exemplification in the accompanying drawing in the manner following:

igure 1 is an edge of plan view of the sfpring which is of substantially circular orm' Fig 2 is a fragmentary cross section through a piston showing in elevation one of its rings together with an associated spring;

Fig. 3 is a side elevation of one form of the spring;

Fig. 4 1s a fra mentary edge elevation of another form of t e spring; and

Figs. 5 and 6 are fragmentary perspective views of two springs each representing a further modification of this invention.

Referring first of all to Fig. 2, I have shown therein a piston A having on its exterior surface an annular roove 10 wherein is received the usual ring which should be in close fitting engagement with the cylinder wall (not shown). I associate with such a piston ring the present spring G which also is in the general form of a ring tion rearwardly of the piston ring occupying a posiso as to force which tends to maintain the iston'rin closely against the cylinder.

y improved spring may be produced from a relatively thin tempered steel band having a plurality of bends by which the entire band assumes the general form of a polygonal s lit ring. As. shown, these bends 11 occur 0 osely in pairseach defining between them a crimp 12 which is straight, or substantially so. Each crimp is preferably annealed or softened for a purpose which will appear hereinafter. Between the crimps are greater exert thereon a 5 distances wherein the band may. be straight spring construction,

or reversely curved to provide steps 13, an example of eachform bein suggested in Figures 1 and 4. The ban may further be weakened at each crimp as by the provision of opposite slots 14 extending inwardlyfroin its two edges (see Fig. 3) leaving only a narrow stri of material connecting the adjacent steps. he same result may be attained by punching out openings 15 (see Fig. 5) in which case two narrow connecting strips are left to constitute each crimp; or it may be accomplished by providing staggering slots 16 extending inwardl from the two opposite edges of the spring and (see Fig. 6). In each of these sug ested constructions the slots or openings w ich result in weakening the spring between the stri s are located within the double bonds 11 w ich define the crimps 12. V

In practice, a piston ring sprin such as I have described will be fitted in tie piston groove rearwardly of the piston ring that is also fitted therein. The depth of such a groove may vary greatly-perhaps from 1/64 to 5/32" or more. With the usual the corner or crimp whichinitially stands out boldly is uashed or flattened down when the spring is tted in place behind the piston ring, the degree of such squashing depending largely upon the clearance behind the piston ring. Most of the spring pressure against the ring is exerted at such corners or crimps, but due to their being squashed in when first installed, there is a tendency for the crimps to become prematurely set, i. e., lifeless. In such a spring, moreover, the steps between the crimps perform very little, if.at all, in maintaining a tension against the piston ring, so that when the crimps give out, as above explained, the serviceable life of the spring is exhausted.

By way of contrast, the improved spring of my invention transfers to the steps most of the load which is to be sustained. This comes about from weakening the crimps, and from shaping the steps so that they exert collectively a tension force after the manner of a plurality of lever arms. Up to the time that the spring is installed behind a piston ring,

the several crimps they perform scarcely at all. It is the steps tion and having means by which the band seewhich exert the tension, and because the contions between the steps are rendered weaker necting crimps are relatively weak the steps whereby the steps exert the major tension are free to operate with greater resiliency. force against the ring. 5 I claim: In witness whereof, I have hereunto set 70 1. In combination with a ring fitted withmy hand this 29th day of January, 1929. in the roove of a piston, a spring in the WALTER E. AMBERG.

form 0 a band interposed between the ring and piston, the spring being configured to provide in alternation a series of flat crimps and steps,-relatively weak and strong, respectively, the steps being bent reversely to the curvature of the piston whereby each step intermediately of its ends exerts a pressure against the piston. an

2. In combination with a ring fitted within the groove of a piston, a spring in the form of a band inter osed between the ring and piston, the spring being configured to provide in alternation a series of weakened flat 85 I crimps and reversely bent steps, the latter ing'required to' exert the major tension force against the ring.

3. Incombination with a ring fitted within the groove of a piston, a spring inthe form 00 of a band interposed between the ring and piston, the spring-being configured to provide in alternation a series of crimps and steps the former having a cross sectional area l are weakened to require the steps to exert the major force against the spring.

4. In combination with a ring fitted within the groove of a piston, a s ring in the form 5 of a steel band interposed between the ring and piston, the spring being shaped to present a series of points bearing with opposite pressures against the ring and, piston, and treated to provide tempered and softened 40 polgigns at various places throughout its l en a i 5. In combination with a ring fitted with- ,in the oove of a piston, a spring in the form-o a steel band interposed between the 45 ring and piston, the spring being confi ured to provide in alternation a series of so tened crimgws and tempered reversely bent steps, the ormer bearing against the ring and the latter'against the piston. I

50 6. In combination with a ring fitted within the oove of a piston, a spring in the form 0 a band interposed betweenthe ring and piston, the spring being configuredto provide in alternationa series of crimps and 55 steps, relatively weak and strong, respective- I ly, the weakened crimp portions between their points of connection ,with the steps being spaced from the ring whereby to avoid bearing and wear at such weakened places.

o0 7. In combination with'a ring fitted with in the groove of a piston, a springin the form of a band interposed between the ring and piston, the spring being configured to provide in alternation a series of crimps and 66 steps, the latter having a uniform cross secess than the latter whereby the crimps i u v 

